[PATCH] D81930: [AArch64] Add -mmark-bti-property flag.
This revision was automatically updated to reflect the committed changes.
Closed by commit rG95e43f84b7b9: [AArch64] Add -mmark-bti-property flag.
(authored by danielkiss).
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D81930/new/
https://reviews.llvm.org/D81930
Files:
clang/include/clang/Driver/Options.td
clang/lib/Driver/ToolChains/Clang.cpp
clang/test/Driver/arm64-markbti.S
llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
Index: llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
===
--- llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
+++ llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
@@ -33,6 +33,9 @@
/// Emit contents of constant pool for the current section.
void emitCurrentConstantPool();
+ /// Callback used to implement the .note.gnu.property section.
+ void emitNoteSection(unsigned Flags);
+
/// Callback used to implement the .inst directive.
virtual void emitInst(uint32_t Inst);
Index: llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
===
--- llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
+++ llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
@@ -11,12 +11,23 @@
//===--===//
#include "AArch64TargetStreamer.h"
+#include "AArch64MCAsmInfo.h"
+#include "AArch64Subtarget.h"
+#include "llvm/BinaryFormat/ELF.h"
#include "llvm/MC/ConstantPools.h"
+#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCSection.h"
+#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/Support/CommandLine.h"
using namespace llvm;
+static cl::opt MarkBTIProperty(
+"aarch64-mark-bti-property", cl::Hidden,
+cl::desc("Add .note.gnu.property with BTI to assembly files"),
+cl::init(false));
+
//
// AArch64TargetStreamer Implemenation
//
@@ -37,8 +48,50 @@
ConstantPools->emitForCurrentSection(Streamer);
}
-// finish() - write out any non-empty assembler constant pools.
-void AArch64TargetStreamer::finish() { ConstantPools->emitAll(Streamer); }
+// finish() - write out any non-empty assembler constant pools and
+// write out note.gnu.properties if need.
+void AArch64TargetStreamer::finish() {
+ ConstantPools->emitAll(Streamer);
+
+ if (MarkBTIProperty)
+emitNoteSection(ELF::GNU_PROPERTY_AARCH64_FEATURE_1_BTI);
+}
+
+void AArch64TargetStreamer::emitNoteSection(unsigned Flags) {
+ if (Flags == 0)
+return;
+
+ MCStreamer = getStreamer();
+ MCContext = OutStreamer.getContext();
+ // Emit a .note.gnu.property section with the flags.
+ MCSectionELF *Nt = Context.getELFSection(".note.gnu.property", ELF::SHT_NOTE,
+ ELF::SHF_ALLOC);
+ if (Nt->isRegistered()) {
+SMLoc Loc;
+Context.reportWarning(
+Loc,
+"The .note.gnu.property is not emitted because it is already present.");
+return;
+ }
+ MCSection *Cur = OutStreamer.getCurrentSectionOnly();
+ OutStreamer.SwitchSection(Nt);
+
+ // Emit the note header.
+ OutStreamer.emitValueToAlignment(Align(8).value());
+ OutStreamer.emitIntValue(4, 4); // data size for "GNU\0"
+ OutStreamer.emitIntValue(4 * 4, 4); // Elf_Prop size
+ OutStreamer.emitIntValue(ELF::NT_GNU_PROPERTY_TYPE_0, 4);
+ OutStreamer.emitBytes(StringRef("GNU", 4)); // note name
+
+ // Emit the PAC/BTI properties.
+ OutStreamer.emitIntValue(ELF::GNU_PROPERTY_AARCH64_FEATURE_1_AND, 4);
+ OutStreamer.emitIntValue(4, 4); // data size
+ OutStreamer.emitIntValue(Flags, 4); // data
+ OutStreamer.emitIntValue(0, 4); // pad
+
+ OutStreamer.endSection(Nt);
+ OutStreamer.SwitchSection(Cur);
+}
void AArch64TargetStreamer::emitInst(uint32_t Inst) {
char Buffer[4];
Index: llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
===
--- llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
+++ llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
@@ -223,26 +223,9 @@
return;
// Emit a .note.gnu.property section with the flags.
- MCSection *Cur = OutStreamer->getCurrentSectionOnly();
- MCSection *Nt = MMI->getContext().getELFSection(
- ".note.gnu.property", ELF::SHT_NOTE, ELF::SHF_ALLOC);
- OutStreamer->SwitchSection(Nt);
-
- // Emit the note header.
- emitAlignment(Align(8));
- OutStreamer->emitInt32(4); // data size for "GNU\0"
- OutStreamer->emitInt32(4 * 4); // Elf_Prop size
- OutStreamer->emitInt32(ELF::NT_GNU_PROPERTY_TYPE_0);
- OutStreamer->emitBytes(StringRef("GNU", 4)); // note name
-
- // Emit the PAC/BTI properties.
- OutStreamer->emitInt32(ELF::GNU_PROPERTY_AARCH64_FEATURE_1_AND);
- OutStreamer->emitInt32(4); // data
[PATCH] D81930: [AArch64] Add -mmark-bti-property flag.
danielkiss marked 4 inline comments as done. danielkiss added a comment. @nickdesaulniers Thanks for the review, comments are addressed. CHANGES SINCE LAST ACTION https://reviews.llvm.org/D81930/new/ https://reviews.llvm.org/D81930 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[PATCH] D81930: [AArch64] Add -mmark-bti-property flag.
danielkiss updated this revision to Diff 291922.
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D81930/new/
https://reviews.llvm.org/D81930
Files:
clang/include/clang/Driver/Options.td
clang/lib/Driver/ToolChains/Clang.cpp
clang/test/Driver/arm64-markbti.S
llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
Index: llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
===
--- llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
+++ llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
@@ -33,6 +33,9 @@
/// Emit contents of constant pool for the current section.
void emitCurrentConstantPool();
+ /// Callback used to implement the .note.gnu.property section.
+ void emitNoteSection(unsigned Flags);
+
/// Callback used to implement the .inst directive.
virtual void emitInst(uint32_t Inst);
Index: llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
===
--- llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
+++ llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
@@ -11,12 +11,23 @@
//===--===//
#include "AArch64TargetStreamer.h"
+#include "AArch64MCAsmInfo.h"
+#include "AArch64Subtarget.h"
+#include "llvm/BinaryFormat/ELF.h"
#include "llvm/MC/ConstantPools.h"
+#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCSection.h"
+#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/Support/CommandLine.h"
using namespace llvm;
+static cl::opt MarkBTIProperty(
+"aarch64-mark-bti-property", cl::Hidden,
+cl::desc("Add .note.gnu.property with BTI to assembly files"),
+cl::init(false));
+
//
// AArch64TargetStreamer Implemenation
//
@@ -37,8 +48,50 @@
ConstantPools->emitForCurrentSection(Streamer);
}
-// finish() - write out any non-empty assembler constant pools.
-void AArch64TargetStreamer::finish() { ConstantPools->emitAll(Streamer); }
+// finish() - write out any non-empty assembler constant pools and
+// write out note.gnu.properties if need.
+void AArch64TargetStreamer::finish() {
+ ConstantPools->emitAll(Streamer);
+
+ if (MarkBTIProperty)
+emitNoteSection(ELF::GNU_PROPERTY_AARCH64_FEATURE_1_BTI);
+}
+
+void AArch64TargetStreamer::emitNoteSection(unsigned Flags) {
+ if (Flags == 0)
+return;
+
+ MCStreamer = getStreamer();
+ MCContext = OutStreamer.getContext();
+ // Emit a .note.gnu.property section with the flags.
+ MCSectionELF *Nt = Context.getELFSection(".note.gnu.property", ELF::SHT_NOTE,
+ ELF::SHF_ALLOC);
+ if (Nt->isRegistered()) {
+SMLoc Loc;
+Context.reportWarning(
+Loc,
+"The .note.gnu.property is not emitted because it is already present.");
+return;
+ }
+ MCSection *Cur = OutStreamer.getCurrentSectionOnly();
+ OutStreamer.SwitchSection(Nt);
+
+ // Emit the note header.
+ OutStreamer.emitValueToAlignment(Align(8).value());
+ OutStreamer.emitIntValue(4, 4); // data size for "GNU\0"
+ OutStreamer.emitIntValue(4 * 4, 4); // Elf_Prop size
+ OutStreamer.emitIntValue(ELF::NT_GNU_PROPERTY_TYPE_0, 4);
+ OutStreamer.emitBytes(StringRef("GNU", 4)); // note name
+
+ // Emit the PAC/BTI properties.
+ OutStreamer.emitIntValue(ELF::GNU_PROPERTY_AARCH64_FEATURE_1_AND, 4);
+ OutStreamer.emitIntValue(4, 4); // data size
+ OutStreamer.emitIntValue(Flags, 4); // data
+ OutStreamer.emitIntValue(0, 4); // pad
+
+ OutStreamer.endSection(Nt);
+ OutStreamer.SwitchSection(Cur);
+}
void AArch64TargetStreamer::emitInst(uint32_t Inst) {
char Buffer[4];
Index: llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
===
--- llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
+++ llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
@@ -223,26 +223,9 @@
return;
// Emit a .note.gnu.property section with the flags.
- MCSection *Cur = OutStreamer->getCurrentSectionOnly();
- MCSection *Nt = MMI->getContext().getELFSection(
- ".note.gnu.property", ELF::SHT_NOTE, ELF::SHF_ALLOC);
- OutStreamer->SwitchSection(Nt);
-
- // Emit the note header.
- emitAlignment(Align(8));
- OutStreamer->emitInt32(4); // data size for "GNU\0"
- OutStreamer->emitInt32(4 * 4); // Elf_Prop size
- OutStreamer->emitInt32(ELF::NT_GNU_PROPERTY_TYPE_0);
- OutStreamer->emitBytes(StringRef("GNU", 4)); // note name
-
- // Emit the PAC/BTI properties.
- OutStreamer->emitInt32(ELF::GNU_PROPERTY_AARCH64_FEATURE_1_AND);
- OutStreamer->emitInt32(4); // data size
- OutStreamer->emitInt32(Flags); // data
- OutStreamer->emitInt32(0); // pad
-
- OutStreamer->endSection(Nt);
- OutStreamer->SwitchSection(Cur);
+ if
[PATCH] D81930: [AArch64] Add -mmark-bti-property flag.
nickdesaulniers added a comment.
I don't have any thoughts on the change per se, so just minor thoughts/generic
code review.
Comment at: clang/lib/Driver/ToolChains/Clang.cpp:6995
+ case llvm::Triple::aarch64_be:
+if (Arg *A = Args.getLastArg(options::OPT_mmark_bti_property)) {
+ CmdArgs.push_back("-mllvm");
it looks like `A` is unused. Should we be using `Args.hasFlag` instead of
`Args.getLastArg`?
Comment at: llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp:56-58
+ if (MarkBTIProperty) {
+emitNoteSection(ELF::GNU_PROPERTY_AARCH64_FEATURE_1_BTI);
+ }
The coding style allows for the curly braces to be omitted for single statement
bodies.
Comment at: llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp:64
+return;
+ }
+ MCStreamer = getStreamer();
ditto
Comment at: llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp:68
+ // Emit a .note.gnu.property section with the flags.
+ MCSection *Cur = OutStreamer.getCurrentSectionOnly();
+ MCSectionELF *Nt = Context.getELFSection(".note.gnu.property", ELF::SHT_NOTE,
move this to just before the SwitchSection call below?
Comment at: llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h:40
+ /// Callback used to implement the .note.gnu.property section.
+ virtual void emitNoteSection(unsigned Flags);
+
does this need to be virtual?
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[PATCH] D81930: [AArch64] Add -mmark-bti-property flag.
chill accepted this revision. chill added a comment. This revision is now accepted and ready to land. LGTM. It'd be nice if we could get someone non-Arm to have a look too. though. CHANGES SINCE LAST ACTION https://reviews.llvm.org/D81930/new/ https://reviews.llvm.org/D81930 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[PATCH] D81930: [AArch64] Add -mmark-bti-property flag.
danielkiss updated this revision to Diff 288765.
danielkiss marked an inline comment as done.
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D81930/new/
https://reviews.llvm.org/D81930
Files:
clang/include/clang/Driver/Options.td
clang/lib/Driver/ToolChains/Clang.cpp
clang/test/Driver/arm64-markbti.S
llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
Index: llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
===
--- llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
+++ llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
@@ -36,6 +36,9 @@
/// Callback used to implement the .inst directive.
virtual void emitInst(uint32_t Inst);
+ /// Callback used to implement the .note.gnu.property section.
+ virtual void emitNoteSection(unsigned Flags);
+
virtual void EmitARM64WinCFIAllocStack(unsigned Size) {}
virtual void EmitARM64WinCFISaveFPLR(int Offset) {}
virtual void EmitARM64WinCFISaveFPLRX(int Offset) {}
Index: llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
===
--- llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
+++ llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
@@ -11,12 +11,23 @@
//===--===//
#include "AArch64TargetStreamer.h"
+#include "AArch64MCAsmInfo.h"
+#include "AArch64Subtarget.h"
+#include "llvm/BinaryFormat/ELF.h"
#include "llvm/MC/ConstantPools.h"
+#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCSection.h"
+#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/Support/CommandLine.h"
using namespace llvm;
+static cl::opt MarkBTIProperty(
+"aarch64-mark-bti-property", cl::Hidden,
+cl::desc("Add .note.gnu.property with BTI to assembly files"),
+cl::init(false));
+
//
// AArch64TargetStreamer Implemenation
//
@@ -37,8 +48,52 @@
ConstantPools->emitForCurrentSection(Streamer);
}
-// finish() - write out any non-empty assembler constant pools.
-void AArch64TargetStreamer::finish() { ConstantPools->emitAll(Streamer); }
+// finish() - write out any non-empty assembler constant pools and
+// write out note.gnu.properties if need.
+void AArch64TargetStreamer::finish() {
+ ConstantPools->emitAll(Streamer);
+
+ if (MarkBTIProperty) {
+emitNoteSection(ELF::GNU_PROPERTY_AARCH64_FEATURE_1_BTI);
+ }
+}
+
+void AArch64TargetStreamer::emitNoteSection(unsigned Flags) {
+ if (Flags == 0) {
+return;
+ }
+ MCStreamer = getStreamer();
+ MCContext = OutStreamer.getContext();
+ // Emit a .note.gnu.property section with the flags.
+ MCSection *Cur = OutStreamer.getCurrentSectionOnly();
+ MCSectionELF *Nt = Context.getELFSection(".note.gnu.property", ELF::SHT_NOTE,
+ ELF::SHF_ALLOC);
+ if (Nt->isRegistered()) {
+SMLoc Loc;
+Context.reportWarning(
+Loc,
+"The .note.gnu.property is not emitted because it is already present.");
+return;
+ }
+
+ OutStreamer.SwitchSection(Nt);
+
+ // Emit the note header.
+ OutStreamer.emitValueToAlignment(Align(8).value());
+ OutStreamer.emitIntValue(4, 4); // data size for "GNU\0"
+ OutStreamer.emitIntValue(4 * 4, 4); // Elf_Prop size
+ OutStreamer.emitIntValue(ELF::NT_GNU_PROPERTY_TYPE_0, 4);
+ OutStreamer.emitBytes(StringRef("GNU", 4)); // note name
+
+ // Emit the PAC/BTI properties.
+ OutStreamer.emitIntValue(ELF::GNU_PROPERTY_AARCH64_FEATURE_1_AND, 4);
+ OutStreamer.emitIntValue(4, 4); // data size
+ OutStreamer.emitIntValue(Flags, 4); // data
+ OutStreamer.emitIntValue(0, 4); // pad
+
+ OutStreamer.endSection(Nt);
+ OutStreamer.SwitchSection(Cur);
+}
void AArch64TargetStreamer::emitInst(uint32_t Inst) {
char Buffer[4];
Index: llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
===
--- llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
+++ llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
@@ -221,26 +221,9 @@
return;
// Emit a .note.gnu.property section with the flags.
- MCSection *Cur = OutStreamer->getCurrentSectionOnly();
- MCSection *Nt = MMI->getContext().getELFSection(
- ".note.gnu.property", ELF::SHT_NOTE, ELF::SHF_ALLOC);
- OutStreamer->SwitchSection(Nt);
-
- // Emit the note header.
- emitAlignment(Align(8));
- OutStreamer->emitInt32(4); // data size for "GNU\0"
- OutStreamer->emitInt32(4 * 4); // Elf_Prop size
- OutStreamer->emitInt32(ELF::NT_GNU_PROPERTY_TYPE_0);
- OutStreamer->emitBytes(StringRef("GNU", 4)); // note name
-
- // Emit the PAC/BTI properties.
- OutStreamer->emitInt32(ELF::GNU_PROPERTY_AARCH64_FEATURE_1_AND);
- OutStreamer->emitInt32(4); // data size
-
[PATCH] D81930: [AArch64] Add -mmark-bti-property flag.
chill added inline comments. Comment at: llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCAsmInfo.cpp:106 + + EmitBTIMarking = MarkBTIProperty.getValue(); } No need to the `.getValue()` part. Comment at: llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCAsmInfo.h:34 explicit AArch64MCAsmInfoELF(const Triple ); + bool EmitBTIMarking; }; Is there a need for this data member? The option value does not change over time, and the option can be defined in `AArch64TargetStreamer.cpp`. CHANGES SINCE LAST ACTION https://reviews.llvm.org/D81930/new/ https://reviews.llvm.org/D81930 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[PATCH] D81930: [AArch64] Add -mmark-bti-property flag.
danielkiss marked an inline comment as done. danielkiss added inline comments. Comment at: llvm/lib/Target/AArch64/AArch64.td:352 +def FeatureEmitNoteBTIProperty : SubtargetFeature<"markbtiproperty", "MarkBTIProperty", +"true", "Emit .note.gnu.property for Branch Target Identification" >; chill wrote: > No, this is an abuse of subtarget features. Subtarget features represent > characteristics of the chip, they shouldn't be used to pass arbitrary bits of > information. > Possible alternatives - `TargetOptions` (cf. > `BackendUtil.cpp:initTargetOptions()`) or > LLVM command-line arguments (cf. `BackendUtil.cpp:setCommandLineOpts()`. Thanks, now I learned how to pass flags across layers, that was not clear at the first time. CHANGES SINCE LAST ACTION https://reviews.llvm.org/D81930/new/ https://reviews.llvm.org/D81930 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[PATCH] D81930: [AArch64] Add -mmark-bti-property flag.
danielkiss updated this revision to Diff 285492.
danielkiss added a comment.
Fix review comments.
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D81930/new/
https://reviews.llvm.org/D81930
Files:
clang/include/clang/Driver/Options.td
clang/lib/Driver/ToolChains/Clang.cpp
clang/test/Driver/arm64-markbti.S
llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCAsmInfo.cpp
llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCAsmInfo.h
llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
Index: llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
===
--- llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
+++ llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
@@ -36,6 +36,9 @@
/// Callback used to implement the .inst directive.
virtual void emitInst(uint32_t Inst);
+ /// Callback used to implement the .note.gnu.property section.
+ virtual void emitNoteSection(unsigned Flags);
+
virtual void EmitARM64WinCFIAllocStack(unsigned Size) {}
virtual void EmitARM64WinCFISaveFPLR(int Offset) {}
virtual void EmitARM64WinCFISaveFPLRX(int Offset) {}
Index: llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
===
--- llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
+++ llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
@@ -11,8 +11,13 @@
//===--===//
#include "AArch64TargetStreamer.h"
+#include "AArch64MCAsmInfo.h"
+#include "AArch64Subtarget.h"
+#include "llvm/BinaryFormat/ELF.h"
#include "llvm/MC/ConstantPools.h"
+#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCSection.h"
+#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSubtargetInfo.h"
using namespace llvm;
@@ -37,8 +42,56 @@
ConstantPools->emitForCurrentSection(Streamer);
}
-// finish() - write out any non-empty assembler constant pools.
-void AArch64TargetStreamer::finish() { ConstantPools->emitAll(Streamer); }
+// finish() - write out any non-empty assembler constant pools and
+// write out note.gnu.properties if need.
+void AArch64TargetStreamer::finish() {
+ ConstantPools->emitAll(Streamer);
+
+ MCContext = getStreamer().getContext();
+ const AArch64MCAsmInfoELF *MCAI =
+ static_cast(Context.getAsmInfo());
+
+ if (MCAI->EmitBTIMarking) {
+emitNoteSection(ELF::GNU_PROPERTY_AARCH64_FEATURE_1_BTI);
+ }
+}
+
+void AArch64TargetStreamer::emitNoteSection(unsigned Flags) {
+ if (Flags == 0) {
+return;
+ }
+ MCStreamer = getStreamer();
+ MCContext = OutStreamer.getContext();
+ // Emit a .note.gnu.property section with the flags.
+ MCSection *Cur = OutStreamer.getCurrentSectionOnly();
+ MCSectionELF *Nt = Context.getELFSection(".note.gnu.property", ELF::SHT_NOTE,
+ ELF::SHF_ALLOC);
+ if (Nt->isRegistered()) {
+SMLoc Loc;
+Context.reportWarning(
+Loc,
+"The .note.gnu.property is not emitted because it is already present.");
+return;
+ }
+
+ OutStreamer.SwitchSection(Nt);
+
+ // Emit the note header.
+ OutStreamer.emitValueToAlignment(Align(8).value());
+ OutStreamer.emitIntValue(4, 4); // data size for "GNU\0"
+ OutStreamer.emitIntValue(4 * 4, 4); // Elf_Prop size
+ OutStreamer.emitIntValue(ELF::NT_GNU_PROPERTY_TYPE_0, 4);
+ OutStreamer.emitBytes(StringRef("GNU", 4)); // note name
+
+ // Emit the PAC/BTI properties.
+ OutStreamer.emitIntValue(ELF::GNU_PROPERTY_AARCH64_FEATURE_1_AND, 4);
+ OutStreamer.emitIntValue(4, 4); // data size
+ OutStreamer.emitIntValue(Flags, 4); // data
+ OutStreamer.emitIntValue(0, 4); // pad
+
+ OutStreamer.endSection(Nt);
+ OutStreamer.SwitchSection(Cur);
+}
void AArch64TargetStreamer::emitInst(uint32_t Inst) {
char Buffer[4];
Index: llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCAsmInfo.h
===
--- llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCAsmInfo.h
+++ llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCAsmInfo.h
@@ -31,6 +31,7 @@
struct AArch64MCAsmInfoELF : public MCAsmInfoELF {
explicit AArch64MCAsmInfoELF(const Triple );
+ bool EmitBTIMarking;
};
struct AArch64MCAsmInfoMicrosoftCOFF : public MCAsmInfoMicrosoft {
Index: llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCAsmInfo.cpp
===
--- llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCAsmInfo.cpp
+++ llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCAsmInfo.cpp
@@ -30,6 +30,11 @@
cl::values(clEnumValN(Generic, "generic", "Emit generic NEON assembly"),
clEnumValN(Apple, "apple", "Emit Apple-style NEON assembly")));
+static cl::opt MarkBTIProperty(
+"aarch64-mark-bti-property", cl::Hidden,
[PATCH] D81930: [AArch64] Add -mmark-bti-property flag.
chill requested changes to this revision. chill added inline comments. This revision now requires changes to proceed. Herald added a subscriber: dang. Comment at: llvm/lib/Target/AArch64/AArch64.td:352 +def FeatureEmitNoteBTIProperty : SubtargetFeature<"markbtiproperty", "MarkBTIProperty", +"true", "Emit .note.gnu.property for Branch Target Identification" >; No, this is an abuse of subtarget features. Subtarget features represent characteristics of the chip, they shouldn't be used to pass arbitrary bits of information. Possible alternatives - `TargetOptions` (cf. `BackendUtil.cpp:initTargetOptions()`) or LLVM command-line arguments (cf. `BackendUtil.cpp:setCommandLineOpts()`. CHANGES SINCE LAST ACTION https://reviews.llvm.org/D81930/new/ https://reviews.llvm.org/D81930 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[PATCH] D81930: [AArch64] Add -mmark-bti-property flag.
danielkiss updated this revision to Diff 272024.
danielkiss retitled this revision from "[AArch64] Add -mbti flag." to
"[AArch64] Add -mmark-bti-property flag.".
danielkiss edited the summary of this revision.
danielkiss added a comment.
Rename the flag to -mmark-bti-property
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D81930/new/
https://reviews.llvm.org/D81930
Files:
clang/include/clang/Driver/Options.td
clang/lib/Driver/ToolChains/Arch/AArch64.cpp
clang/test/Driver/arm64-markbti.S
llvm/lib/Target/AArch64/AArch64.td
llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
llvm/lib/Target/AArch64/AArch64Subtarget.h
llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
Index: llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
===
--- llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
+++ llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
@@ -20,6 +20,7 @@
class AArch64TargetStreamer : public MCTargetStreamer {
public:
AArch64TargetStreamer(MCStreamer );
+ AArch64TargetStreamer(MCStreamer , const MCSubtargetInfo *STI);
~AArch64TargetStreamer() override;
void finish() override;
@@ -36,6 +37,9 @@
/// Callback used to implement the .inst directive.
virtual void emitInst(uint32_t Inst);
+ /// Callback used to implement the .note.gnu.property section.
+ virtual void emitNoteSection(unsigned Flags);
+
virtual void EmitARM64WinCFIAllocStack(unsigned Size) {}
virtual void EmitARM64WinCFISaveFPLR(int Offset) {}
virtual void EmitARM64WinCFISaveFPLRX(int Offset) {}
@@ -56,6 +60,7 @@
private:
std::unique_ptr ConstantPools;
+ const MCSubtargetInfo *STI;
};
class AArch64TargetELFStreamer : public AArch64TargetStreamer {
@@ -65,7 +70,8 @@
void emitInst(uint32_t Inst) override;
public:
- AArch64TargetELFStreamer(MCStreamer ) : AArch64TargetStreamer(S) {}
+ AArch64TargetELFStreamer(MCStreamer , const MCSubtargetInfo *STI)
+ : AArch64TargetStreamer(S, STI) {}
};
class AArch64TargetWinCOFFStreamer : public llvm::AArch64TargetStreamer {
@@ -76,8 +82,8 @@
// Symbol of the current epilog for which we are processing SEH directives.
MCSymbol *CurrentEpilog = nullptr;
public:
- AArch64TargetWinCOFFStreamer(llvm::MCStreamer )
-: AArch64TargetStreamer(S) {}
+ AArch64TargetWinCOFFStreamer(llvm::MCStreamer , const MCSubtargetInfo *STI)
+ : AArch64TargetStreamer(S, STI) {}
// The unwind codes on ARM64 Windows are documented at
// https://docs.microsoft.com/en-us/cpp/build/arm64-exception-handling
Index: llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
===
--- llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
+++ llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
@@ -11,8 +11,12 @@
//===--===//
#include "AArch64TargetStreamer.h"
+#include "AArch64Subtarget.h"
+#include "llvm/BinaryFormat/ELF.h"
#include "llvm/MC/ConstantPools.h"
+#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCSection.h"
+#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSubtargetInfo.h"
using namespace llvm;
@@ -21,7 +25,13 @@
// AArch64TargetStreamer Implemenation
//
AArch64TargetStreamer::AArch64TargetStreamer(MCStreamer )
-: MCTargetStreamer(S), ConstantPools(new AssemblerConstantPools()) {}
+: MCTargetStreamer(S), ConstantPools(new AssemblerConstantPools()),
+ STI(nullptr) {}
+
+AArch64TargetStreamer::AArch64TargetStreamer(MCStreamer ,
+ const MCSubtargetInfo *STI)
+: MCTargetStreamer(S), ConstantPools(new AssemblerConstantPools()),
+ STI(STI) {}
AArch64TargetStreamer::~AArch64TargetStreamer() = default;
@@ -37,8 +47,54 @@
ConstantPools->emitForCurrentSection(Streamer);
}
-// finish() - write out any non-empty assembler constant pools.
-void AArch64TargetStreamer::finish() { ConstantPools->emitAll(Streamer); }
+// finish() - write out any non-empty assembler constant pools and
+// write out note.gnu.properties if need.
+void AArch64TargetStreamer::finish() {
+ ConstantPools->emitAll(Streamer);
+ if (!STI)
+return;
+
+ if (STI->getFeatureBits()[AArch64::FeatureEmitNoteBTIProperty]) {
+emitNoteSection(ELF::GNU_PROPERTY_AARCH64_FEATURE_1_BTI);
+ }
+}
+
+void AArch64TargetStreamer::emitNoteSection(unsigned Flags) {
+ if (Flags == 0) {
+return;
+ }
+ MCStreamer = getStreamer();
+ MCContext = OutStreamer.getContext();
+ // Emit a .note.gnu.property section with the flags.
+ MCSection *Cur = OutStreamer.getCurrentSectionOnly();
+ MCSectionELF *Nt = Context.getELFSection(".note.gnu.property", ELF::SHT_NOTE,
+
